Validation of ShipIR (v4.2)

Abstract

Numerous improvements have been made to various sub-models in the NATO-standard and USN accredited naval ship infrared signature model (ShipIR) since its last validation in SPIE using ShipIR (v3.2). These include upgrades to MODTRAN5 and MODTRAN6 for the sun, sky, and atmosphere models, and various fixes and improvements to the sea model: corrections to the Fresnel sea reflectance formula (v3.3a), empirical 2nd-order hiding (v3.4), and a recent fix to the sea surface roughness slope distribution (v4.2). This paper will revisit the previous experimental results, used to validate ShipIR (v3.2), first comparing these results against the steady-state version of the thermal solver in ShipIR (v4.2) and complementing these with the transient thermal solver introduced in ShipIR (v4.0).